The NFL Players Association recently announced a five-year partnership with WHOOP in which every active player will be provided with a device. NBA players like DeAndre Jordan and Matthew Dellavedova are so enamored with their WHOOPs that they've worn them during games despite the fact they weren't necessarily permitted to do so (it's anticipated that the new CBA, which kicks in on July 1, could allow in-game wearable use).

Prior to the start of the 2017 season, WHOOP became "the first continuous product of its kind" to be approved for in-game use by Major League Baseball. That decision came on the heels of WHOOP completing a study that involved 230 minor league players across nine MLB organization, making it the largest performance study ever conducted with a professional U.S. sports league.

If so many pros are wearing it, the WHOOP's gotta be good, right?

The company sent me one of their WHOOP 2.0 units so I could get a better understanding of how the device works and the insights it can provide. The WHOOP is meant to be worn constantly, as it features an attachable battery that lets you recharge the unit while you wear it. The unit is comfortable enough and the app is intuitive, but no one's going to shell out $500 for a glorified bracelet. Luckily, the WHOOP is much more than that. Here are five things I learned after spending a few weeks with the wearable of the future.

1. A New Respect for Different Ways to Sweat

When it comes to working out, I'm a fairly simple guy. I lift. I run. Sometimes I do yoga. That's about it. The WHOOP helped me realize how changes in tempo and intensity in my own training have a drastic effect on my heart rate and calories burned. I saw the big difference in terms of efficiency between high-intensity interval hill runs—where I once burned close to 500 calories in roughly 30 minutes while establishing a new max heart rate of 195—and steady state runs with little elevation changes. The latter often left me disappointed with my total calories burned—I guess I'm the type of person who likes his workouts fast, hard and effective.

While the WHOOP helped me better understand how to approach my traditional training methods, it also gave me a new appreciation for different ways to get in shape. One Saturday, I found myself mountain biking with my WHOOP equipped. This was probably the second time I've ever been mountain biking in my life. It was good exercise on a warm day, but I was amazed at just how many calories I burned on the bike. The 45-minute session helped me burn 4,840 calories on the day, far above my usual average of roughly 3,000. For a dude who's starting to get sick of the basic ways to stay in shape, that was a breath of fresh air. I've since begun mountain biking more frequently.

2. Alcohol Wreaks Havoc on Your Recovery

Every morning, WHOOP greets you with a sleep performance score on a scale of 1-100. It's a quick way to help you understand just how restful your sleep was, as the WHOOP tracks factors like how many sleep cycles you went through throughout the night and how many times your sleep was disturbed. I received a 78% one morning after clocking a solid night's sleep which included 1 hour and 23 minutes of REM sleep. REM sleep is very important, as it plays a key role in cognitive learning, information processing and higher-level thought.

One way to sabotage your sleep? Alcohol before bed. One Saturday night after having some adult beverages, I clocked a pathetic 40% sleep score. I clocked just 35 minutes of REM sleep that night. According to the National Sleep Foundation, while alcohol can help you fall asleep faster (my sleep onset latency on the aforementioned night was just two minutes), it also blocks REM sleep. This occurs because alcohol can activate a type of brain pattern not normally present during sleep known as alpha activity. The closer to bed time you imbibe, the more severe the effects will be. The average WHOOP user reportedly consumes alcohol before bed 79% less often after wearing the device for at least four months.

3. A Sleep Score Brought Out My Competitive Side

As a former college athlete, I like quantifying success. I liked looking at the box score to see how many receptions or yards I totaled after a good game. I liked the feeling of hanging 50 points on an opponent. In training, I like seeing how many Pull-Ups I can do in a set or how quickly I can run a mile. I'm sure most athletes or fitness junkies feel the same way.

If there's one thing the WHOOP will help you realize, it's that sleep is just as important—if not more so—than training. By quantifying my sleep performance, WHOOP helped motivate me to invest in sleep. Sure, I'd known about the effects a good night's sleep can have—improved athletic performance, more energy, faster recovery, less stress, etc.—before I wore a WHOOP. But the incentive of receiving an actual rating for my sleep proved to be quite powerful. Like any competitive person, I wanted to score high. When I did score high, I felt both renewed and rewarded. NBA star Blake Griffin also found the WHOOP's sleep tracker to be immensely helpful. "The big thing for me is the sleep coach," Griffin told ESPN. "It gives you the extra confidence that you're rested and ready." The average WHOOP user reportedly gets an additional 41 minutes of sleep per night after wearing the device for at least four months.

4. You Don't Have to Work Out to Have a Strenuous Day

I've always tended to think of my day in two ways when it came to fitness—either I worked out or I didn't. If I did work out on a given day, I felt good about my effort. If I didn't, I felt lazy and unproductive.

WHOOP assigns a "day strain" score to users for every day they wear the device. That score is defined as "a summary measurement of the exertion placed on your cardiovascular system in a given day." The scale runs from 0-21, with anything below a 10 being classified as a "light" day and anything above 18 being classified an "all out" day. Since our bodies burn calories even while we're asleep, I didn't find it unusual to wake up and find that my day strain score was already at 5 or so. WHOOP helped me realize that missing a workout doesn't automatically doom your day from an activity standpoint. I found there'd be days where I didn't "work out" in the traditional sense but ended up logging a higher day strain score than some days where I did work out. Attending events like concerts or NBA playoff games had a significant effect on my heart rate and therefore, my day strain score. I realized it was possible to have a very strenuous day without every really "working out"—or at least working out in the way I've come to think of it.

5. No One's 100% All The Time

Ever feel like your legs are filled with lead during a run? I know I have. Ordinarily, I would chalk this up to me being out of shape or perhaps eating the wrong thing before I trained. But the WHOOP helped me realize that everyone has days where they aren't at 100%—that's just how life goes. This device was measuring things like my sleep, resting heart rate, heart rate variability and skin temperature. If it tells me I'm not in the position to push myself on a given day, who am I to argue?

So instead of beating myself up for not being at my best, I accepted the biological facts and aimed to come back stronger the next day. That resignation helped me feel OK with not crushing every workout, which ultimately felt like a smarter approach to fitness. There are going to be days when you're ready to set new PRs and there are going to be days when you're not—and the WHOOP helped me better differentiate between the two. Perhaps that's why the average WHOOP user experiences reported injuries 60% less often after wearing the device for at least four months.

Even as an average Joe who's longer involved with high-level competitive sports, the WHOOP helped me better understand my body and prioritize what's really important. If you're interested in learning more about this cutting-edge device, head to WHOOP.com.

Brandon Hall
- Brandon Hall is an Assistant Content Director for STACK. He graduated from Lafayette College, where he played football and graduated with a Bachelor's degree in English.
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